Create a dummy user in znc to use as a skel/clone identity: /msg *controlpanel adduser zncclone somepassword

Configure this user how you want them. Mainly use your above zncadmin account to disable their flag access to bind.

Configure cyrusauth module: (/msg *cyrusauth help)

Set cyrusauth module to use it the cloneuser: cloneuser yourcloneusernamehere

Let it create users: createuser Yes

Your services/ircd need to provide an account to auth as, which can set the users account on IRC (Impersonization). In X3/nefarious this is the I flag in authserv. Create an account with this flag and set its details here: setimpersonateaccount znc somepassword

A network to configure for cloned users: setNetworkName yournetwork

A server to configure for them: setServer irc.yournetwork.org 6697 true

Salt is used to unpredictibly hash usernames: set UserSalt somethingrandom